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A+ Guide to Hardware, 4e

Chapter 10

PCs on a Network

A+ Guide to Hardware, 4e 2

Objectives

• Learn about different types of physical network

architectures

• Learn how networking works with Windows

• Learn how to install a network card and connect to a

network

• Learn how to set up and secure a wireless network

• Learn about troubleshooting tools and tips for

network connections


Introduction

• Topics covered in this chapter:

– Technologies used to build networks

– How Windows supports a network connection

– How to connect a computer to a network

– How switches and routers interface networks

– How to setup and secure a wireless network

– How to troubleshoot a network connection


Physical Network Architectures

• Elements providing an overview of networks

– The different sizes of networks

– The different technologies used by networks

– Some networking terms

• Network types commonly encountered

– Ethernet

– Wireless networks

– Telephone networks

– Mostly outdated token ring and FDDI networks


Sizes of Networks

• A network links two or more computers

• PAN (personal area network)

– Consists of personal devices at close range

• LAN (local area network)

– Covers a small local area such as a home, or office

• MAN (metropolitan area network)

– Covers a large campus or city

• WAN (wide area network)

– Covers a large geographical area; e.g., the Internet


Networking Technologies

• Factors driving network evolution:

– The type of data the network is intended to support

– The data capacity on the network

– How a network is to fit among other networks

• Bandwidth (data throughput or line speed):

– Analog systems: measured in cycles/sec (hertz or Hz)

– Digital systems: measured in bps, Kbps, or Mbps

• As networks grow, the need for bandwidth grows


Additional Terms Used in Networking

• Node (host): one device on a network; e.g., server

• Network adapter: interfaces a PC with a network

– Network interface card (NIC): fits in a PCI slot

• Adapter (MAC, physical, or hardware) address:

– 48-bit (6-byte) id number hard-coded on card

– Example: 00-0C-6E-4E-AB-A5

• Network protocols: rules of communication

• Packets (datagrams or frames)

– Basic unit of data transmitted on a network


Figure 10-1 Ethernet network card showing its MAC address


Introducing Ethernet

• Ethernet types (categorized by speed):

– 10-Mbps Ethernet

– 100-Mbps or Fast Ethernet

– 1000-Mbps or Gigabit Ethernet

– 10-Gigabit Ethernet

• Types of cabling used:

– Two kinds of twisted-pair

• Unshielded twisted pair (UTP): four pairs of twisted wire

• Shielded twisted pair (STP): protected from EMI

– Coaxial cable: single copper wire with braided shield

– Fiber-optic: glass strands inside protective tubing


Table 10-2 Variations of Ethernet and Ethernet cabling


Figure 10-4 Fiber-optic cables contain a glass core for

transmitting light


Introducing Ethernet (continued)

• Topology: arrangement of nodes in a network

• Bus topology: connects all nodes with a line (no hub)

• Star topology

– Connects nodes to central hub (or switch)

– The hub broadcasts a data packet to every device

– Switch uses a table to route packet to receiving device

• Scale networks by adding switches

• Star bus topology:

– Multiple switches form a bus network

– Nodes connected to each switch form a star


Figure 10-6 Nodes on an Ethernet network can be connected to one

another in a star or bus formation


Figure 10-10 A star bus network uses more than one switch


Introducing Ethernet (continued)

• Attenuation: the weakening of a transmitted signal

• Repeater: device used to amplify a signal in a LAN

• Amplifier repeater: simply amplifies incoming signal

• Signal-regenerating repeater

– Reads and copies the signal (without noise)

– Transmits an exact duplicate of the original

• Ethernet uses a signal-regenerating repeater

– A switch or hub can act as the repeater


Figure 10-14 A repeater on a network restores the clarity of the signal,

which degrades over a distance because of attenuation


Wireless Networks

• Use radio waves or infrared light to connect PCs

• Popular in places where cables are difficult to install

• 802.11wireless (Wi-Fi or Wireless Fidelity)

– Types: 802.11g (most popular), 802.11b, 802.11a

– Two new standards: 802.11k and 802.11r

– Ad hoc mode: directly links two wireless devices

– Access point (AP): connects wireless device to LAN

• WiMAX (802.16 Wireless/802.16d and 802.16e)

– Used in public hot spots and as a last mile solution

• Bluetooth: short range standard; e.g., optical mouse


Figure 10-16 Nodes on a wireless LAN connect to a cabled network by

way of an access point


Telephone Networks

• Plain old telephone service (POTS)

– Switching creates closed circuits between phones

• VoIP (Voice over Internet Protocol)

– Uses packets of data to communicate

• Cellular WAN

– Made up cells created by base stations

• Cellular WAN standards

– GSM (Global System for Mobile Communications)

– CDMA (Code Division Multiple Access)

– TDMA (Time Division Multiple Access)


Figure 10-20 A cellular WAN is made up of many cells

that provide coverage over a wide area


Telephone Networks (continued)

• General Packet Radio Service (GPRS)

– New communication protocol using data packets

• Two types of transmission:

– Full-duplex: allows both users to talk and transmit

– Half-duplex: allows only one user on a channel

• Satellite phone: communicates with satellites

• Cordless phone: communicates with phone base

• Radio phone: uses VHF radio waves


Token Ring and FDDI

• Token Ring is physically a star, logically a ring

• Components of a token ring:

– Controlled Access Unit (CAU)

– Multistation Access Unit (MSAU or MAU)

– Token Ring LAN card connecting node to MSAU

– UTP or STP cables with two twisted pairs

– RJ-45 or Universal Data Connector (UDC)

• Fiber Distributed Data Interface (FDDI)

– Uses a token that travels in a ring like a Token Ring

– Data frames travel on the ring without the token


Figure 10-21 Full-duplex and half-duplex transmissions


Windows on a Network

• Major software components on a network

• An operating system installed on each PC

– Network operating system (NOS) for larger networks

• Peer-to-peer network (workgroup)

– Each PC has the same authority on the network

• Client/server model (domain)

– Access to network resources controlled by an NOS

– Server is called a domain controller

• A few network operating systems

– Windows 2003 Server, Novell NetWare, Linux


Four Suites of Protocols

• TCP/IP (Transmission Control Protocol/Internet

Protocol)

– Primary protocol used on the Internet

• IPX/SPX (Internetwork Packet Exchange/Sequenced

Packet Exchange)

– Designed for use with Novell NetWare

• NetBEUI (NetBIOS Extended User Interface)

– Supports NetBIOS (Network Basic Input/Output System)

• AppleTalk

– Proprietary networking protocol suite for Macs


Figure 10-25 An operating system can use more than one method to

address a computer on the network, but at the network level, a MAC

address is always used to address a device on the network


Four Suites of Protocols (continued)

• Using a protocol on the network

– Install a NIC card in the computer

– Connect network cable to network device; e.g., a switch

– NIC card binds to higher level protocol; e.g., TCP/IP

• How to identify which protocols are used in Windows

– Look at the properties of a network connection

• More than one OS protocol can be used on a network

• New protocols may be installed

• Network printers can be accessed in various ways


Figure 10-26 Three Windows XP network protocols are installed and two

protocols are bound to this network card


Addressing on a Network

• Four methods used to identify devices and programs

– Using a MAC address

– Using an IP address

– Using character-based names (host, domain, NetBIOS)

– Using a Port address

• IP addresses

– Used in TCP/IP to identify any device on the network

– 4 bytes (octets) separated by dots; e.g., 190.180.40.120

– System allows for up to 4.3 billion IP addresses

– First part identifies network, last part identifies host


Figure 10-27 Computers on the same LAN use MAC addresses to

communicate, but computers on different LANs use IP addresses to

communicate over the Internet


Installing a NIC and Connecting to a

Network

• Components needed to connect a PC to a network

– NIC and network port or wireless NIC card in the PC

– Patch cable

– Device for the PC to connect to, such as a router

• NIC card selection criteria

– NIC should match type of bus on motherboard

– NIC should match speed and type of network

– Wireless NIC should match network technology


Installing a NIC Using Windows

2000/XP

• Overview of installation steps

– Determine whether driver or NIC is installed first

– If NIC precedes driver, install NIC and turn on PC

– Follow instructions in Found New Hardware Wizard

– Verify driver installation using the Device Manager

– Update the driver if necessary

– Connect patch cable to NIC port and network switch

• Configuring Windows 2000/XP to use a network

– Name computer in System Properties dialog box


Figure 10-32 Windows XP uses the Computer Name Changes dialog box to

assign a host name to a computer on a network



2000/XP (continued)

• Questions to ask before configuring TCP/IP

– Will the PC use dynamic or static IP addressing?

– What are the IP address, subnet mask, default gateway?

• A question to ask if static IP addressing is used

– Do you use DNS?

• If so, what are the IP addresses of your DNS servers?

– Is a proxy server used to connect to other networks?

• If so, what is the IP address of the proxy server?

• Gateway: device that connects two networks



2000/XP (continued)

• Internet Protocol (TCP/IP) Properties dialog box

– Used to configure TCP/IP under Windows XP

– Dialog opened from Properties of Local Area Connection

• NWLink or NetBEUI protocol

– Used for network communication (excluding the Internet)

– Can be used in combination with TCP/IP

– Installed from Properties of Local Area Connection


Figure 10-34 To configure TCP/IP under Windows XP, use the

Internet Protocol (TCP/IP) Properties dialog box


Installing a NIC Using Windows 9x/Me

• Overview of installation steps:

– Physically install the NIC and turn on the PC

– Follow instructions of the Wizard

– Verify the installation using Device Manager

• Assigning a computer name

– Access Identification tab in Network dialog box

– Enter names of computer and workgroup

– Verify assignment in Network Neighborhood window

• Installing and configuring TCP/IP using Windows 98

– Use functions in the Network window


Figure 10-40 To configure TCP/IP in Windows 98, select the binding and click

Properties to view the TCP/IP Properties dialog box


Installing a Wireless Adapter in a

Notebook

• Wireless adapter uses a USB port or PC Card slot

• Installation package includes a CD and accessories

• Overview of steps for installing a Linksys adapter

– Install the software from the setup CD

– Plug the wireless adapter into a USB port

– Launch Found New Hardware and follow instructions

• Managing the issue of an unsigned driver

– Find approved driver or continue installation

• Deciding which installation utility to use

– Choose manufacturer’s utility over Windows XP’s


Figure 10-45 Plug the wireless USB adapter into the USB port



Notebook (continued)

• Information displayed about a current connection:

– MAC address of access point device used by adapter

– The current channel the connection is using

– Transfer rate, throughput, link quality, signal strength

• Configuration changes you can make:

– Mode or network type

– The SSID (service set identifier)

– Encryption settings

– Tx rate

– TCP/IP configuration


Figure 10-49 Opening screen to configure a Linksys wireless adapter



Notebook (continued)

• Connecting to a public hot spot using Windows XP

– Open Wireless Network Connection dialog box

– Select unsecured network from list and click Connect

– Open a browser to test the connection

– View link in Wireless Network Connection Status box

• Two ways to troubleshoot a connection

– Add network SSID in Wireless network properties

– Provide MAC address to network administrator


Figure 10-57 Enter the SSID of a hot spot to which you want to connect


How to Set Up Your Own Wireless

Network

• Two principal steps:

– Buy a wireless access point

– Configure AP and wireless PC for communication

• Providing security is critical for a successful network


Security on a Wireless LAN

• Methods for securing a wireless connection:

– Disable SSID broadcasting

– Filter MAC addresses

– Data encryption; e.g., WPA (WiFi Protected Access)

– Change firmware default settings

– Update firmware

– Use a firewall

– Virtual private network (VPN)


Figure 10-60 With tunneling, packets can travel over a wireless LAN and

the Internet in a virtual private network (VPN), but WEP or WPA applies

only to the wireless connection


Choosing a Wireless Access Point

• Selection criteria

– The ability to use multiple security measures

– Supports for the 802.11 b/g wireless standards

– Good hardware reviews from other users

• An access point can be a standalone device

• An access point can also serve multiple purposes


Configure and Test Your Wireless

Network

• Installing the hardware

– Position device and plug it in

– Connect the device using a network or USB cable

• Access point configuration is saved on firmware

• Configuring the access point

– Change default password to the administrative utility

– Select basic wireless settings, such as the channel

– Set up data encryption

– Choose whether to filter MAC addresses

– Save the settings and test the connection


Figure 10-65 This wireless access point supports several encryption methods


Troubleshooting a Network

Connection

• Some symptoms indicating a faulty NIC:

– You cannot make a connection to the network.

– My Network Places does not show any other PCs

– An error message displays during driver installation

• Displaying TCP/IP connection information

– Use Ipconfig under Windows 2000/XP

– Use Winipcfg under Windows 9x/Me

• Ping (Packet Internet Groper) diagnostic tool

– Sends a signal to a remote computer

– If remote PC is online and senses signal, it responds


Summary

• Network: system interconnecting two or more PCs

• Basic network types: PANs, LANs, MANs, and WANs

• Bandwidth: amount of data transmitted per unit time

• Ethernet topologies: bus, star, star bus

• Wireless standards: 802.11g/b/a/k/r, WiMAX,

Bluetooth


Summary (continued)

• Telephone technologies: POTS, VoIP, Cellular WAN,

satellite phone, cordless phone, and radio phone

• OS level protocols: TCP/IP, IPX/SPX, Net BEUI,

AppleTalk

• IP address: 32-bit address identifying network node

• Local Area Connection dialog box: used to install

and modify communication protocols

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